Fire-proof shutter



G. L. DAMON.

Patented Dec. 27,1881.

UNITED STATES PATENT OFFICE.

GEORGE L. DAMON, OF BOSTON, MASSACHUSETTS.

FIRE-PROOF SHUTTER.

SPECIFICATION forming part of Letters Patent No. 251,528, dated December 27, 1881.

' 2 Application filed August 25, 1881. (No model.)

To all whom it may concern Be it known that I,'GEORGE L. DAMON, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented Improvements in Fire-Proof Shutters, of which the following is a specification.

The invention relates to that class of fireproof shutters in which a metallic frame or casing is employed to contain asbestus and plaster or other suitable fire-proof material or composition, leaving the smallest possible surface of metal exposed on the outside.

My improved shutter is made with a false back and a space between this and the true back, through which space free circulation of air is permitted and will be caused by heat, a hereinafter described.

In the accompanying drawings, Figure 1 is a rear perspective view of my improved shutter. Fig. 2 is a front perspective view of the metallic shell or frame thereof, partly in section. Fig. 3 is a vertical section of the complete shutter.

The top, bottom, and sides A may be made of either cast or sheet metal, flanged to retain the fire-proof filling B, which is further supported and secured therein by anchoring-studs C. These parts may be constructed and ar ranged as in fire-proof shutters already in use. Instead, however, of applying the fire-proof fillingB directlyin contact with the true back of the shutter, I employa false back, I), which formsthe rear wall ofthe com position-chamber, and to which the anchoring-studs O are fixed.

' Between the false back D and the true back E of the shutter is a space, F, the free passage and circulation of air through which prevent the overheating of the parts or the communication of an injurious degree of heat to the shutter-back E. Air is admitted freely to and from the space F by openings G G around the edges of the shutter or openings H in the back E, or preferably both.

In the event of a eonfiagraiion the heating of the outside of the shutter will cause an active'current of air through the space F, cool air from within the building being admitted through the openings H in the lower part of the shutter-back, to supply the place of the warm air which passes out above through the openings G.

I am aware that it is not broadly new to protect metallic shutters with fire-proof material.

Having thusdescribed my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

1. The combination of the shell A D, fireproof filling B, back E, and air-space F, substantially as and for the purpose set forth.

2. In a fire-proof shutter having an external filling,B, ofincombustible and non-conducting material, the air-space F and suitable apertures, H G, for admitting air at the lower part from the interior of the building and discharging it above, substantially as set forth.

GEO. L. DAMON.

Witnesses:

WILMON W. BLACKMAR, URIAH A. POLLARD. 

